Guard for throwing wheels



Oct. 27, 1959 K. H. BARNES v 2,909,870

GUARD FOR THRowING- WHEELS v Filed Jan. so, 1957 felice/llaa abrasive particles are thrown from the wheel.

United States Patent C) GUARD FOR THROWING WHEELS Kenneth H. Barnes, South Bend, Ind., assignor to Wheelabrator Corporation, Mishawaka, Ind., a corporation of Nebraska Application January 30, 1957, Serial No. 637,188 7 Claims. (c1. s19) This invention relates to a machine for throwing abrasives at high velocity onto a surface to be cleaned, eroded, or otherwise treated, and it relates more particularly to a multi-bladed wheel which is rotated at high speed for throwing'abrasive particles bycentrifugal force onto the surfaces to be cleaned, and this invention is still more particularly addressed to the protection of surfaces about .the wheel to prevent such surfaces from being eaten away by the thrown abrasive particles. l For a full description of throwing wheels embodied in the practice of this invention, reference may be made to vthe' previously issued patents to Peik No. 2,104,055, Turnbull No. 2,131,772, and Straub No. 2,708,814, and the copending application of Barnes, Serial No.v 583,135, filed May 7, 1956, covering an improvement in the blade assembly in a multibladed centrifugal blasting wheel. Briefly described, the wheel comprises a plurality of radially' arranged blades which extend crosswise in equally spaced `apart relation between la pair of spaced disc members mounted for rotational movement at high speed together :on a driving shaft. The blades, which extend inwardly radially from the periphery of the wheel, terminate short of the center to provide a circular opening therebetween dirnensioned to receive a stationary cage having a feed opening therethrough and an impeller within the cage which rotates with the wheel.

By providing an outlet opening in the cage through 'which the abrasive particles may be thrown by the impeller 'to be taken up by the inner ends of the throwing blades, it has become possible to control the area from which the While such control, by adjustment of the cage, is effective for the large majority of the abrasives processed through the wheel, it is impossible to restrict all the free-flowing abrasive to a particular section of the wheel so that small fractions of the abrasive particles will be thrown at high velocity from other peripheral portions of the wheel. If this small fraction is ignored completely, it will be found that the walls of the housing in which the wheel is conliined will be soon eaten away by the abrasive to the extent that'holes willappear and particles of abrasive will find 'their way out into the atmosphere to waste abrasive, Vendanger personnel and otherwise introduce serious consequences and objections.

Thus, it is essential to enclose the wheel within a housing lcapable of standing up for a long time under the wear of the abrasives. In the meantime, it is very desirable to enable easy access to be had to the wheel elements for replacement and repair of parts, as frequently required because of the very nature of its operation and the mate- 'rials on which. it operates. To'the present, these combinations of characteristics including protection of the hous- 'ing from wear, sealing of the housing to prevent abrasives from being thrown out into the atmosphere, and ready disassembly of the protective elements to enable access to thewheel for the replacement of parts or repair have not V been made available, and it therefore is an object of this invention to produce a wheel assembly of the type deice scribed having a protective structure embodying the described characteristics.

More specifically, it is an object of this invention to produce an assembly of the type described which is formed of relatively few simple parts that are easily assembled in position lof use to protect the walls of the housing about the throwing wheel; which provides a sealed relation between parts to prevent the escape of abrasive particles to the atmosphere surrounding the wheel; which enables easy and full access to the wheel for replacement and repair of parts; which does not in any way interfere vwith the operation of the throwing wheel; which is easily and efliciently secured in the assembled relation to prevent displacement of parts in operation, thereby to maintain a desired sealing relationship; and in which the parts are easily interchangeable with others for replacement of worn parts without loss of the sealing relationship and without loss in the protection provided by the guard assembly.

These and other objects and advantages of this invention will hereinafter appear and, for purposes of illustration but not of limitation, reference will be made to the accompanying drawing, in which- Figure 1 is a perspective elevational view of a wheel assembly embodying the features of this invention with parts broken away to show the interior construction thereof and to illustrate its mounting upon a cleaning housing;

Figure 2 is a sectional elevational view through the center of the wheel assembly shown in Figure 1;

Figure 3 is a sectional View taken along the line 3 3 of Figure 2; and

Figure 4 is a sectional View taken along the line 4-4 of Figure 2.

Referring now to the drawing, the centrifugal throwing wheel is represented by a plurality of throwing blades 10 extending crosswise between disc plates 12 and 14 having equally spaced-apart facing grooves 16 extending radially in the inner walls of the disc members for receiving the lateral edges 18 of the blades 10, thereby to mount the blades radially in equally spaced-apart relation in the wheel. The blades 10 extend inwardly from the periphery of the disc members to a distance short of the axis to dene a circular opening therebetween. A stationary cage (not shown) having a feed opening in the cylindrical wall thereof is fixed in the circular opening by attachment to a'portion of the housing supporting the wheel. Within the cage there is provided an impeller (not shown) which is fixed to the hub of the wheel for rotational movement with the wheel and which is formed with multiple vanes for advancing the abrasive particles fed onto the inner surfaces of the impeller to the cage for passage through the described opening.

The abrasive-particles advanced by the vaned impeller through the feed opening in the stationary cage are picked up `by the inner ends of the blades 10 as they pass by. The abrasive particles are caused to be advanced outwardly along the surfaces of the blades 10 as they rotate rapidly with the wheel until the abrasive is thrown at high centrifugal force from the ends of the blades. By proper selection of the location of the opening in the cage, it is possible to dene the area from which most of the abrasive particles will be thrown from the wheel, thereby to make more efficient and effective use of the abrasive.

Thewheel is mounted with its axis adjacent the outer wall ofthe main housing 20 so that a large portion of the wheel extends outwardly of the housing while a segment projects into the housing. The portion of the throwing wheel outside of the main housing is enclosed within `a wheel housing. The problem is to confine the wheel within a guard to protect both the walls of the wheel housing and the main housing from hte spray of abrasive particles thrown from the periphery of the wheel and, for this4 purpose, it is desirable to provide a guard which not only covers the walls of the wheel housing but which also extends about the portions of the throwing wheel projecting into the main housing.

The wheel is thus intended to be confined within the main housing 2li nad the wheel housing 22 to which there is iiXed a feed hopper 2d having a chute 26 which leads downwardly from the iced hopper to the opening at one end of the vaned impeller. A driving means is mounted adjacent the opposite wall of the housing 22, as represented by the shaft 255 which is journalled within a bearing 3@ and which is provided at its outer end with a plurality of sheaves 32 for receiving driving belts interconnecting the sheaves or pulleys with a driving motor. The other end of the shaft is joined to the hub of the throwing wheel for rotating the wheel and the vaned impeller at high speed about their common axis within the housing.

The wheel housing per se is formed with upright side walls 34 and 36 spaced laterally a short distance from the discs l2 and i4 of "ie wheel, and it is formed further of upwardly and inwardly inclined front and back walls 38 and t? joi d at their lateral edges to the side walls. The top and bottom of the wheel housing are left open for access through the top to the wheel and for access through the bottoni for throwing the abrasive downwardly from the wheel onto the work.

While the parts will bear same relationship one to the other in the assembly hereinafter defined, they may be otherwise disposed when the wheel is otherwise mounted e r on the side walls, the bottom wall, or the front or back walls of the main housing instead of at the top, as described. lt will be understood that the same concepts to be described herein will be applicable no matter what direction in which the abrasive is intended to be thrown by the wheel.

The surfaces of the housings about the wheel are to be protected from abrasive particles thrown el by a plurality of separate elements which einafter be d ibed and which are formed of material, such as fully heatlybdenum alloy steels as marketed or Corporation of lvlishawaka, Indiana Q t af n is .ri and Jo Oi wheel housing are lined e and ani i plate 44, each of which other to the at, ent wall of the housing members 46 with spacers between the ain spaced relation between the inner the latter of which tits e plate members are prefals, g s l nt linss radiating from the asis or the w eel into sections which are more easily handled for place. .ent into positions or use and for removal of su h orents singly or together for replacement or repair. e drawing, illustration is made of a side wall liner 9^ formed of four separable parts divided into seg r g the vertical center and along a line radiating outwardly and upwardly from .ne center, with the lower segments being dimensioned to extend downwardly beyond the ends of the wheel housing into portions ci the ho '1g for a distance corresponding at least to count which the wheel extends into the main housin s of the s .er plates as a. rail 58 l portion et? between the rail and the aion of the wheel housing with the outer plate 4?. therebetween.

Referring now to the elements forming the front and back walls of the wheel housing, only one set of which will hereinafter be described because of the identical constructions thereof, it will be apparent from the description,

as illustrated in Fig. 4 of the drawing, that a continuous spaced relation exists crosswise adjacent the inner face of the front and back wall members between the face of the wall and the rails 5S of the side wall plates 42 and 44.

The liner plates 62 which constitute a part of the front and back walls are shaped to fill the spaced relation dened between the rails 58 and the adjacent walls, being dimensioned to have a width corresponding to the spaced relation between the inner faces of the side walls 34 and 36 of the wheel housing, and thickness corresponding to the distance between the front or back wall 40and the outer edges of the outer plate members 42, with grooves 64 provided in the inner faces of the liner plate 62 dimensioned in width to correspond to the width of the inner liner plate 44 and in depth to correspond with the offset of the plate edge forming the rail to receive the rails in fitting relationship therein. The intermediate portions 62a of the section 62 between the inner plates 44 and in peripheral alignment with the throwing wheel are of greater thickness than the remainder so as to project still further into the area between the plates to provide a more substantial intertting relationship with the side guard plates 44 and to provide increased thickness of metal where the greatest forces of abrasion from the thrown adhesive materials will be aiected. The liner plates for the front and back walls are divided into a lower section 62h and an upper section 62C. Each lower section 62h is formed with grooves 66 extending lengthwise in the outer faces of the edge portions from the lower end to a point adjacent the upper end to enable displacement of the lower plate lengthwise downwardly through the formed slot 68 over `the ends of studs 70 fixed in laterally spaced apart relation on the housing to extend in the groove in position to lie in the path of a shoulder 72 at the end of the groove to provide a stop for the plate section against further relative downward movement from its lowered position of adjustment. Upon insertion, the lower plate rides on the rails 58 downwardly through the slot until the shoulder 72 is engaged by the stud 7) to tix the plate in its assembled relation with the lower end portions of the plate 62 extending downwardly beyond the top wall of the main housing by an amount corresponding to that of the side plates and as limited by the dimensional relationship between the length of the plate, the length of the recess 66 formed therein, and the location of the stop stud '70 in the lower portion of the wheel housing adjacent the top of the main housing. The upper edge portion of the lower plate 62b is notched or mitered as at 74 to receive its counterpart in the form of a projection 76 in the lower end of the upper section 62C to provide an intertting relation at their meeting edges.

The upper edge of the upper plates 62 terminate with an outer portion at a level corresponding to the level of the outer liner plate 42 and an inner portion at about the level of the rail edge of the inner liner plate 44 to provide a continuation of the groove 60 between the rail and the adjacent side, front and back walls of the wheel housing.

The cover plate comprises a single metal member 7S dimensioned to be smaller in length and width than the length and width of the opening at the top of the wheel housing to enable displacement therethrough onto the assembled liner plates. The top plate is dimensioned to correspond in width to the distance between the outer liner plates 42 and in length to the distance between the front and back liner plates 62 at their upper end. A. recess in the form of a groove Si) is provided in the bottom side of the top plate dimensioned to receive the rail sections all around in tting relation therein. The upper corner portions of the outer liner plates 44 are notched, as at S2, and the equivalent portion of the top plate inwardly of the recess is dimensioned to have a greater cross-section to be received in ltting relation within said notches. This operates not only firmly to position the top plate-but it functions.V in addition to create a sealed relationship whichv minimizes the wear on the lining members. y l y y The top plate 78 is held in place by a cover 84 in the form of a fiat member dimensioned to fit over the top of the'housing. The cover is formed `with notches 86 in its ends for receiving fastening means releasably to hold the cover in position of use. Various fastening means may be employed, suchv as the bolt members 88 pivotally mounted at their ends upon a spindle 90 operating within a bracket 92 fixed to the front and back walls of the housing adjacent their upper edges in position to enable the bolt to be rocked upwardly about its pivot into the formed notch 86. Caps 94 dimensioned to be larger in crosssection than the notches are threadably received on the threaded end of the bolt member 88 for enabling turning movement to tighten the cover plate onto the housing.

In assembly, the side plates 42 and 44 are fixed, as by the bolt means 46, in position of use onto the side walls 34 and 36 of the wheel housing. The plates 62b are then fitted with their grooves 64 in sliding relation on the rails 58 in the lateral edges of the side plates so that the plates 62b may be displaced by sliding movement'downwardly along the rails through the slotted end portion 68 until the stop 70 enters the groove 66 and engages the shoulder 72 to hold the plate 62b in its lowered position of adjustment. After the plates 62b have thus properly been positioned, the top sections of the end plates, namely the plates 62, may be similarly mounted with their grooves 64 on the rails 58 to enable sliding movement of the plates 62" downwardly through the slot 68 in the end sections of the housing until coming to rest in abutting relationship with the top edges of the bottom plates 62h.

Thus the linings confronting the front and back walls of the wheel housing are located in position of use to protect the walls of the housing. The top plate 78 may merely be positioned by lowering the plate through the opened end of the housing onto the top edges of the side and end plates with the rail members 58 of the top and end plates received in fitting relationship within the recess 80 that is provided in the closure member. When thus assembled, the cover plate may then be located over the opening and the bolt will be rotated upwardly through the slot 86 so that the nut members 94 can be turned resiliently to urge the cover 84 downwardly against the wheel housing while also preventing the bolt member from being rocked inadvertently from latching position to unlatching position.

Disassembly to remove one or more of the elements may be effected by carrying out the steps in reverse order to remove the cover 84, the exposed top plate 78, and the end plates 62c and 62b respectively by sliding movement on the rails. Then the side plates can be disengaged from the side walls of the housing by removal of the bolt members.

The insertion of an element such as the rails 58 into a recess, such as the grooves 64 and 80, as between the elements, not only provides for an interfitting relationship to stabilize the assembly but its more important function is to militate against particles of abrasive being thrown through the interfaces between the elements to engage the walls of the housing or to be thrown out into the atmosphere. In the described interfitting relationship, the particles of abrasive would be required to change directionsl several times before passage from the interior to the exterior of the wheel housing to engage the walls of the housing or to pass out into the atmosphere. By the time that the abrasive particles are able to make their way through the offset interconnecting sections of the guard plates, the abrasive particles would have lost all vof their force so that wear, ifany, on the wheel housing walls would be reduced to a minimum.

' It will be apparent Vfurther that the blocks of which the liner guard is formed are capable of assembly or disassembly in a simple and efficient mannerby reason of the fact that the described interfitting means are employed as distinguished from bolt and nut means which might become frozen in position of use lunder the conditions existing to resist removal. Thus the interior of the housing and the guard members can be periodically inspected for the replacement of those which have-been subjected to greater wear or to gain access to the interior of the housing for the replacement of blades of the wheel or for repair or replacement of wheel parts.

It will be understood that the description herein is confined chiefiy to the throwing wheel and the protective elements associated therewith to minimize Wear on the cleaning machine parts, and that changes may be made in the details of construction, arrangement and operation without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. In a machine having a multi-bladed Wheel mounted for rotational movement at high speed for throwing abrasive particles from the periphery thereof and a wheel housing about the Wheel formed of side and end walls and which is open at the top and open at the bottom for passage of the abrasive thrown from the wheel downwardly onto the work, a guard assembly for protecting the walls of the housing from Wear by the abrasive material and for preventing abrasive material from being thrown out into the atmosphere, comprising a plurality of side plate members of wear-resistant material secured to the side walls of the wheel housing and having rails extending outwardly from the inner sections of the outer and upper edges of the assembled side plates to provide a continuous recess between said rails and the side walls of the Wheel housing and in which the side plates terminate short of the top edges of the side walls of the housing and short of the end walls to provide an open space defined between the side walls, rails and end walls, end plates formed of wear-resistant metal dimensioned to have a width corresponding to the spaced relation between the side walls of the wheel housing and a thickness greater than the distance between the endwalls of the wheel housing and the rails on the end edges of the side plates, said end plates having grooves extending continuously through the under side thereof in alignment with said rails in th'e side plates when the end plates are inserted in the open space whereby the rails are Areceived in fitting relation within said grooves, means for stopping the linear downward movement of the end plates when in `position of use thereby gravitationally to hold the end plates in position, a top plate formed of wear-resistant metal dimensioned to have a cross-section less than the cross-section of the opening in the wheel housing but a length and width greater than the lengthwise and crosswise dimension between the side plates and end plates at their upper edges so as to rest on the surfaces thereof, said top plate having a recess spaced inwardly from the edge all around dimensioned to receive the rails in the upper edges of the side and end plates therein in fitting relation, a cover enclosing the open end of the housing, and means for releasably securing the cover in position of use.

2. A machine as claimed in claim 1 in which the end plates are formed at their upper edge with a rail spaced inwardly from the outerredge and extending to a level corresponding to the rails in the adjacent side plates.

3. A machine as claimed in claim 1 in which the side plate members are rigidly secured by bolt and nut means to the side Walls of the wheel housing.

4. A machine as claimed in claim l in which the side plates are formed of a pair of spaced-apart parallel plates with the inner plate extending outwardly beyond the outer plate to provide the described rail section. I

5. A machine as claimed in claim l in which the end plates are subdivided intor separate elements having their 7 adjacent edges offset one with respect to the other to provide an intertting relation.

6. A machine as claimed in claim 1 in which the lower edges of the end and side plates extend downwardly beyond the wheel housing.

7. A machine as claimed in claim 1 in which the means for holding the end plates in their assembled relation comprises a stop extending inwardly from the end wall of the housing into the path of the plates and a recess in the corresponding outer wall of the plates extending lengthwise through the plate for a distance less than thel length thereof so as to be engaged by the stop at the termina: tion of the recess when in position of use.

References Cited in the le of this patent UNITED STATES PATENTS Lager Dec. 27, -1904 FOREIGN PATENTS Great Britain June 13, 1956 

